JPS5823681B2 - Zetsuendensen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an insulated wire in which an insulating paint containing polyurethane resin as a main component is coated and baked on a conductor.

Polyurethane insulated wires have the disadvantage that crazing occurs when they are stretched, bent, etc., resulting in the formation of 7-pin holes, as well as poor sliding properties and poor windability. There are drawbacks.

As a method for solving these drawbacks, there is a double-covered wire in which nylon 6 or nylon 66 is coated and baked in a polyurethane insulated wire.

However, when this double coated wire is used, windability, slipperiness, etc. can be improved to some extent, but
It also has the disadvantage that crazing occurs when it undergoes processing such as stretching and bending.

Although this drawback can be covered to some extent by performing annealing, it has drawbacks such as an increase in the number of annealing steps and difficult processing conditions.

When winding an insulated wire to form it into a coil,
Since the insulated wire is wound under tension, it is formed into a coil in a somewhat elongated state.In practice, it is almost impossible to form an insulated wire into a coil without elongating it at all. be.

In this manner, when the wire is subjected to stretching, bending, etc. during winding, crazing occurs in the insulating film, and this crazing becomes pinholes, resulting in a decrease in insulation performance.

Although this crazing can be prevented to some extent by annealing, it has the disadvantage of increasing the number of annealing steps.

As a result of intensive research, the inventors found that a double-coated wire made by coating and baking an insulating paint containing nylon 11 or nylon 12 as a main component on a polyurethane insulated wire has good windability and smoothness, and can be stretched and bent. It has been found that the insulated wire is an excellent insulated wire that does not cause crazing after undergoing such processing and does not generate pinholes.

Reference examples and examples are shown below, but the present invention is not limited to the examples.

Reference Example 1 A urethane resin paint was applied to a 0.2 mmφ copper wire by a conventional method and baked to obtain a urethane insulated wire.

Its characteristics are shown in Table 1.

Reference Example 2: A urethane resin paint was applied and baked on a 0.2 mmφ copper wire using a conventional method, and then a nylon 6 paint was further applied and baked to obtain a double-coated electric wire.

Its characteristics are shown in Table 1.

Example 1 A urethane resin paint was coated and baked on a 0.2 mmφ copper wire using a conventional method, and then a nylon 11 paint was coated and baked on top of the coated wire to obtain a double-coated electric wire.

Its characteristics are shown in Table 1.

Example 2 A urethane resin paint was coated and baked on a 0.2 mmφ copper wire using a conventional method, and a nylon 12 paint was further coated and baked on top of the urethane resin paint to obtain a double-coated electric wire.

Its characteristics are shown in Table 1.

As is clear from Table 1, the insulated wire of the present invention generates far fewer pinholes when stretched than the conventional insulated wire.

In other words, the insulated wire of the present invention can suppress the occurrence of crazing even when stretched by stretching, bending, etc. during winding, so it is possible to provide a coil with few pinholes and no fear of deterioration in insulation performance.

[Brief explanation of drawings]

The figure is a cross-sectional view of the insulated wire of the present invention, where 1 is a conductor, 2 is a urethane layer, and 3 is nylon 11 or nylon 12.
This is the layer of

Claims (1)

[Claims] 1. An insulated wire characterized in that an insulating paint mainly composed of polyurethane resin is coated and baked on a conductor, and an insulating paint mainly composed of nylon 11 or nylon 12 is further coated and baked thereon.